Submitted to: International Conference on Mycobacterium bovis
Publication Type: Abstract Only
Publication Acceptance Date: 8/22/2005
Publication Date: 8/22/2005
Citation: Waters, W.R., Palmer, M.V., Thacker, T.C., Payeur, J.B., Minion, F.C., Greenwald, R., Esfandiari, J., Andersen, P., Mcnair, J., Pollock, J.M. 2005. Mycobacterium Kansasii Infection of Cattle Confounds Interpretation of Tuberculosis Diagnostic Tests [abstract]. International Conference on Mycobacterium bovis. p. 26. Interpretive Summary:
Technical Abstract: Cross-reactive responses elicited by exposure to non-tuberculous mycobacteria often confound interpretation of traditional ante-mortem bovine tuberculosis (TB) tests. Use of specific proteins such as ESAT-6, CFP-10, and MPB83 may improve the specificity of these tests in areas where exposure to environmental non-tuberculous mycobacteria is common. However, ESAT-6, CFP-10, and MPB83 are produced by M. kansasii. Instillation of M. kansasii (4 x 10(8) cfu) into the tonsilar crypts of calves elicited delayed type hypersensitivity as well as in vitro interferon-y and nitrite responses to M. avium and M. bovis purified protein derivative (PPD). While responses by M. kansasii-inoculated calves to M. avium and M. bovis PPD were roughly equivalent, responses by M. bovis-infected calves (4 x 10(4) cfu intratonsilarly) to M. bovis PPD exceeded (P < 0.05) respective responses to M. avium PPD. Interferon-y and nitrite responses to rESAT-6:CFP-10 by M. kansasii-inoculated calves exceeded (P < 0.05) corresponding responses by non-inoculated calves beginning 15 and 50 days after inoculation, respectively. Ranking of mean interferon-y and nitrite responses to rESAT-6:CFP-10 by each of the groups generally resulted in M. bovis- > M. kansasii- > non-inoculated cattle. Using a lipoarabinomannan-based enzyme-linked immunosorbent assay (LAM-ELISA), specific serum antibody was detected 50 days after challenge in M. kansasii-inoculated calves but not from animals receiving M. bovis. However, at 124 days after inoculation, antibody responses to LAM by M. bovis-inoculated calves exceeded (P < 0.05) respective responses by M. kansasii-inoculated calves. By multi-antigen print immunoassay, specific antibody responses to MPB83, but not ESAT-6 or CFP-10, were detected in sera from M. kansasii-inoculated calves; however, these responses were notably weak as compared to those elicited by M. bovis infection. These findings indicate that M. kansasii infection of calves elicits specific cellular and humoral responses that may confound interpretation of bovine TB tests using antigens generally considered M. tb complex specific.